Partially, the upstream vendor (Stryker) made some defective knee replacement joints that wear out prematurely, causing pain and issues walking. Opening the kne

Partially, the upstream vendor (Stryker) made some defective knee replacement joints that wear out prematurely, causing pain and issues walking. Opening the knee back up and replacing most of the parts with better designed parts is what has to be done after a decade, then you get to sit there for months and heal.